Fluid-pressure brake system.



F. L. MARSTN. FlUlQ PRESSURE BRAKE SYSTEM.

APPLICATION man JULY 31, |916.

Patented June 11, 1918.

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FRANK L. MARSTON, OF PORTLAND, MAINE.

FLUID-PRESSURE BRAKE SYSTEM.

Specification of Letters Patent.

Patented J une lli, 11918.

Application lec'l July 31, 1916. Serial No. 112,276.

To all 'whom t may concern Be it known that I, FRANK L. MARs'roN, acitizen of the United States, residing at Portland, in the county ofCumberland and State of Maine, have invented certain new and usefulImprovements in Fluid-Pressure Brake Systems, of which the following isa specification.

My invention relates to improvements in fluid pressure braking systemsin which automatic devices, known as triple valves are used.

The objects of my invention are, rst: to eliminate the shock and jar topassengers on a moving train, second: to eliminate the danger ofderailing one or more cars in a moving train upon a curve: third, todecrease the wear and tear on the rolling stock and the strain on thebraking apparatus all of which are caused by the sudden, complete andautomatic application of the brakes to full emergency position upon theaccidental breaking or pulling apart of the train hose, as occurs in thesystems at present in use.

l attain these objects by a combination ofpistons and valves attached toand working with the triple valve of the present systems. Saidcombination is shown in the accompanying drawings and hereafter described as applied to the Westinghouse quick acting triple valve, asused in air brake systems. But I do not restrict my claims to acombination applicable to a quick acting triple valve, nor to thelVestinghouse apparatus, nor to the exact construction as rep resentedin the accompanying drawings or following description,-\vhich isapplicable to Westinghouse apparatus only, but have represented it asthus applied to more fully describe the working parts and the result oftheir action.

No change is made in the l/Vestinghouse triple valve in any of the partsthereof, eX- cepting in the graduating stem, the old plug which screwsinto the opening X at the end of the stem being taken out, and a newplug, embodying all the features of my combination, being screwed intothe aforesaid opemng.

This combination, shown as a whole, and in connection with the generalform of the Westinghouse quick acting triple valve, in Figure l, whichshows all working parts in release position, consists essentially of twocastings 20 and 23, which constitute the shell or main body and containthe working parts. These castings are held together by flange bolts andthe joints are made air tight by gaskets clamped between the castings.

Fig. l is a vertical section of the combination of the Westinghousetriple valve as usually shown in the descriptions of the same, togetherwith my improvements, show-- ino' their working parts.

Fig. lA is a horizontal section of the bot-` tom part of the casting 23with the contained parts taken on the line w-y in Fig. l, and u-fv inFig. 2, showing the valve seat 7" with its port openings. A bottom viewof the slide valve 36 is also shown with its recess s and a portion ofthe rod 26.

Fig. 2 is a view of the inside of 23 with the flat ring 35 removed toshow the pas sage e.

Fig. 3 shows a vertical section of my improvements together with a smallportion of the Westinghouse parts, being a part of Fig. 1, shown in theemergency position but on a larger scale.

Fig. 3A is a horizontal section taken through the center of the rod 21showing a portion of the same passing through the sliding collar 37 andthe ring c which is held in place by a pin passing through the rod andring.

Fig. 3B shows a horizontal section through the center of t-he piston 27,sliding ring 30, the lock nut 28, and a part of the rod 26, showing thepin passing through the rod and nut. The top of the slide valve is shownwith a part of the ianges removed to show the pin which holds the spring25.

Fig. l is a vertical section of the lower part of Fig. 3 in automaticemergency pesition, and Fig. 4A is a View of 7c. 37, and a part of 21 inconnection with the l/Vestinghouse parts in the same relative position.

0n account of the small scale of the drawing as shown in Fig. l, andconsequent ditiiculty of lettering the same, I hereby, in the followingdescription, refer to the detailed views as well as the general viewwhich is depicted in Fig. l.

The large iston in the chamber CZ', having the same iameter as piston 5in the present Westinghouse triple valve, is rigidly attached to the rod2l which passes through the stem of the threaded plug 'forming a part of20, and a movable shoulder 37 engages one end of a spring 22.

A. piston 27 in chamber e is held rigidly against a shoulder on the rod26 by a nut 28. A spring 29 resting against one face of the piston 27holds a movable washer 30 against a shoulder on the rod 26, which passesthrough the spring 29.

.The rod 26 is loosely attached to a slide valve 36 moving in thechamber r. All chambers containing pistons or valves are brass lined.

The chamber r is connected with the pressure chamber H by a small pipescrewed into a threaded opening in chamber 9". The size of this pressurechamber should be governed by the size of the auxiliary reservoirconnected with the chamber of the triple valve proper, and should be soproportioned that the port a would not exhaust the pressure too rapidlyinto the train line when the same is accidentally opened or broken. Theobject of this second auxiliary reservoir is, first: to receive thecompressed air from the train pipe and supply the same to the chamber CZto resist any movement to the right of the piston 211. Second: to supply a propelling force to the piston 27 with its controlling valve 36when the pressure in any manner is reduced in the chamber e.

The tension of the spring 32 which rests in the plug 33 and against theshoulder 3l on rod 26 is equal to a pressure on the face of the piston27 of about 10 pounds to the square inch and can be graduated tocorrespond to the limit of service reduction desired by the plug 33which is locked in the required position by a lock nut 34:.

The tension of] the spring 29 resting 'against the piston 27, and thesliding vcollar 30, is equal to the pressure of about l0 pounds to thesquare inch on the face of the piston 27, or about the differencebetween the reduction of service and the rey duction of emergency.

In the release position of the device, shown in Fig. l, the piston 5 isagainst the shoulders at the extreme left, the slide valve 3 is at theextreme left, the port opening e is closed by the bottom of the chamber,the recess n connects the brake cylinder port fr with the exhaust port Pallowing the brake springs to hold the brakes at release. The piston 27is held at the extreme right by the tension of the spring 32; the recesss in the slide valve 36 is over the exhaust port 7L. The pressure in thetrain line passes in at A, e. g., past the piston 5 by the groove z' tothe chamber m and the auxiliary reservoir B, raising the pressure inthis reservoir to that of the train line, also 'from the train line A,e, a, a to the chamber el', and a to the chamber o', by the groove a tothe chamber r and the pressure chamber H and mesme by port f passage e eto the chamber el equalizing their pressures with the train line.

The service action used in ordinary stops is the saine in the original`Westinghouse parts as it is in the present arrangement. There is noaction n the new partsmy combination. The spring 32 revents any motionin the piston 27 by holt ing it to the extreme right with a force strongenough to overcome the counter force caused by the ordinary servicereduction of pressure in the chamber 0. The pressure in the chamber clremaining nearly the same, would be slightly higher than that in m,which slightly expands when piston 5 moves to the right. The projectionj striking the rod 2l attached to the piston 24E prevents any furthermotion of the piston 5: the action of service and release continues asin the present arrangements.

The emergency action is caused by the engineer throwing his valve leverinto emergency position, and is the same in the West inghouse parts asin the present arrangements. In the new parts which are einbodied in myinvention, the following action takes place: theair in the train line isreduced between l0 and 2O pounds to the square inch by the said actionof the engineer, causing the air to flow by the ports a e, etc., to thetrain line from the chamber 02 until pressure in both are equal. Thenthe pressure in the chamber r and the pressure chamber H being so muchgreater than that in 0, forces the piston 27 with the slide valve 36 tothe let, overcoming the tension of the spring 32 until the collar 30rests in the recess m; the tension of the spring 29 then coming intoellect prevents any further movement of the piston 27 and the slidevalve 36 which is now in such a position that the recess s connects theexhaust port It with the port f allowing the air to' escape from thechamber d by way of passage c c f s to the exhaust port L until thepressure in the chamber cl is the same as that oi" the atmosphere, whenthe piston 5 drives the rod 21 and the piston 2a to the extreme right,overcoming the tension of spring 22 as it does in the presentarrangement. LThe various parts will then be in emergency position asshown in Fig. 3.

The position ol the various Westinghouse parts and their action is thesame as in the present arrangement. The action of rele: se in thelVestinghousc parts is the same as in the present arrangement.' Theaction oi' release in the new parts is as follows:

The pressure being raised in the train line through the engineersvalve,flows in by the passage c e a a to the chamber' o raising the pressureto a point slightly higher than that in the chamber r, allowing thespring 32 to force the piston 27 to the and piston 24 extreme right,returning it with the slide valve to their former positions, and allowing the air in the chamber 1^ and pressure chamber H to flow by the portf and passage e e to the chamber cZ, returning the piston 24tand the rod2l to then' former positions, when it again flows into the chamber r bythe groove n raising the pressure in the pressure chamber H to that inthe train line.

The automatic emergency action is caused by the breaking or pullingapart of the train hose. The air in the train line is exhausted toatmospheric pressure almost instantly. Pressure in 0 exhausts by trainline and passage e e u a to atmosphere, allowing the pressure in 7 whichis nearly as high as formerly, to torce piston 27 rapidly to the extremeleft, overcoming the tension of both springs 32 and 29 and causing theslide valve 36 to rapidly pass the emergency position allowing but aslight reduction of pressure in chamber d by passage e e and port f toexhaust port It while recess s is passing over them, allowing piston 5to force rod 21 and piston 24 to the right until the shoulder lc on rod2l strikes the collar 87 when the spring 22 resists further motion. Theslide valve t now covers the exhaust port t and the recess s connectsport f with recess p allowing the pressure in chamber r t0 pass tochamber eZ under the edge of 36 by recess p s port f and passage e e,again raising the pressure in el to that in the second pressure chamberH. Now the pressure in the auxiliary B has exhausted into the brakecylinder to a point slightly lower than that in the pressure chamber H,and the higher pressure in the chamber ci forces the piston 2e to theleft, driving with it the rod 2l and the pistons 5 and 7 until piston 7closes the port w in slide valve 3 preventing further discharge of airinto the brake cylinder until the air in the chamber d and pressurechamber H exhausts by the port a to a point slightly loweil than that inthe chamber m and the auxiliary B, when the piston 5 will again beforced to the right driving rod 2l with it until again checked by thespring 22, when the piston 24C again covers the port a preventingfurther eX- haust of air from chamber d and pressure chamber H until thepressure in m again exhausts by the port fw which has in the 4mean timebeen opened to the brake cylinder. This operation continues to takeplace until the pressure in the brake cylinder is the same as that inboth chambers. Then, all exhaust ports being closed, the brakes remainset until the pressure in the train line has again been raised, or theair lealrs out oi both the auxiliary reservoir B and the brake cylinderas in the present arrangement.

1t can be readily seen that this repeated opening and closing orp theport w in the slide valve 3 `causes gradual application of the brakes inthe automatic emergency stop, thus accomplishing the objects set forthin the beginning of my description.

What l claim my invention and wish to secure by Letters Patent is thefollowing combination of pistons and valves when applied to triplevalves of Huid pressure braking systems:

l. Means for cushioning the operation of a brake valve comprising acasing having two chambers normally comminiicating with each other atpoints spaced from each other, one chamber having an exhaust port, apiston movably mounted in the other chamber, means fornormally holdingthe piston at an initial position, means for applying uniform pressureat the opposite sides or' the piston when at its initial position and atrest, the said communications between the chambers being so arrangedthat the pressure in both chambers is normally uniform, a valve movablymounted in the chamber having' the exhaust port, a piston movablymounted in the last mentioned chamber between the communicationsconnecting the chambers and connected with the valve, resilient meansfor holding the last mentioned piston at a normal position and the valveat a closed position over the port and means adapted to coperate withthe rst mentioned piston after the beginning of its movement and beforethe end thereof to interrupt the passage of the pressure in that chamberin which it is located and thereby disturbing the balance of thepressure in the ported chamber whereby the piston therein moves thevalve to an open position with relation to the port.

2. Means for cushioning the operation of a brake valve comprising acasing having two chambers normally communicating with each other atpoints spaced from each other, one chamber having an exhaust port, apiston Inova-bly mountedin the @other chamber, means for normallyholding the piston at an initial position, means for ap plying uniformpressure at the opposite sides of the piston when at its initialposition and at rest, the said communications between the chambers beingso arranged that the pressure in both chambers is normally uniform, avalve movably mounted in the chamber having the exhaust port, a pistonmovably mounted in the last mentioned chamber between the communicationsconnecting the chambers with the valve, resilient means for holding thelast mentioned piston at a normal position and valve at a closedposition over the port, the last said chamber being provided with agroove which establishes communication with the opposite ends of thechamber and at the opposite sides ot the last said valve when the sameis at one of its positions, and means adapted to cooperate with the irstmentioned piston after ithe beginning of its movement and before the endthereof to interrupt the passage of the pressure in that chamber inwhich it is located and thereby disturbing the balance of the pressurein the ported chamber whereby the piston therein is moved beyond thegroove and moves the valve to an open position with relation tothe port.

3. In a device as described, a easing having a chamber and provided withan eX- haust port, there being inlet ports communieating with thechamber at points spaced from each other, a piston movably mounted inthe chamber between the inlet ports, a rod Xed in the piston, a springmounted on the rod at a point between the ends thereof and adapted. toencounter the easing when the rod is moved and exert. pressure upon therod, a spring interposed between the rod and casing to hold the rod at anormal pof sition therein, a valve carried by the rod and normallyclosing the exhaust port, the parts being so arranged that the initialmovement of the rod compresses the last mentioned spring and moves thevalve to an open position over the exhaust port, and

the linal movement of the rod compresses .A

the first mentioned spring and moves the valve to a closed position overthe exhaust port.

In testimony whereof l my signature.

' FRANK L. MARSTON Copies of this patent may be obtained for ve centseach, by addressing the Commissioner of Patents, Washington, D. C.

